“Our true mentor in life is science” ……

Father of Turks





We welcome your valuable unpublished research manuscript submissions to my email address for Current works in Mineral Processing, MAYFEB Journal of Chemistry and Chemical Engineering : uulusoy@cumhuriyet.edu.tr !.. (For more details see "Editorships-Journal" Page on the left of the menu!...)


Though flotation was first used in the early 1900s and has undergone extensive research and development, it is still not fully understood and is still comparatively ineffective. Because the flotation process, which is actually fairly complex, is influenced by roughly 100 different factors. Additionally, it makes control more difficult due to the frequent interactions between the flotation factors and the complicated, non-linear correlations among the several factors. Although it might not be essential to manipulate or measure each of these variables at the same time in order to get excellent process control results, each of these factors and how they affect the flotation procedure should be taken into account. In this context, it is suggested that particle properties (size distribution, shape, degree of mineral liberation) are among the most important factors, especially from the point of view of advanced flotation control and optimizing flotation control.


10. Yarar, B., Richter, R. B., 2016, Ullmann’s Encyclopedia of Industrial Chemistry, Flotation, 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, pp. 1-56.


Fig 28 shows us that interfacial properties which is affected by the particle shape, roughness, size etc play a role in the hydrodunamics, energetics and kinetics of the flotation pehnomena.



My research studies aim at the understanding of the particle shape of ground minerals on particle-air bubble adhesion in flotation.


Ore grinding in froth flotation is an important step to liberate the valuable mineral particles from the gangue (Forssberg et al., 1993). When considering particle morphology in minerals processing, comminution is of particular interest as this is the process where the particles attain their morphology which in turn affects classification and separation stages downstream. Studying the morphology characteristics of progeny particles can also be used to interpret breakage mechanisms within milling devices and in some instances, can even be related to the degree of liberation (Leroy et al., 2011). Particle morphology can have an impact on numerous processes through its effect on drag coefficients, rheology, and particle bubble interactions.


Particle surface roughness is the other ones affecting variables on flotation  

Wenzel suggested that the geometry of the surface had a greater effect on the static contact angle than did the chemistry!..


The wettability of real surfaces is subject to many factors, both physical and chemical. For the flotation process, the effect of four main factors; surface roughness, heterogeneity, particle shape, and particle size, on contact angle measurements are of importance (Chau et al., 2009).


T.T. Chau, W.J. Bruckard, P.T.L. Koh, A.V. Nguyen, A review of factors that affect contact angle and implications for flotation practice, Advances in Colloid and Interface Science 150 (2009) 106–115.


Figure: Static contact angle ( advancing angle and the receding) of water on wax substrates, as a function of the substrate roughness (Johnson, Dettre, 1964).


For hydrophobic surfaces the data of Johnson, Dettre, (1964), reported in the Figure above, show the effects of advancing θa (maximum static angle) and receding θr (minimumstatic angle) contact angles of water on surfaces of wax of variable roughness.


As the roughness increases, small variations in the angles, together with significant increases in hysteresis, are observed. Then, both angles suddenly increase as the hysteresis diminished. It was concluded that texturing a solid does not only modify the hysteresis but it can also affect dramatically the value of the mean contact angle itself.


Johnson RE, Dettre RH. Adv Chem Ser 1964;43:112–35.


Wotruba et al. [1991] reported contradiction results from flotation tests carried out on zircon samples before and after attritioning for 48h in a planetary mill. It was noted that the particle shape remained unchanged by the attritioning and only the particle surfaces were roughened. It was shown that the freshly roughened material floated in total far better than the original material.


Wotruba H, Hoberg H, Schneider FU. XVIIth Int Miner ProcessCong IV 1991:83–95.


Successful particle–bubble attachment involves three steps, viz., 1) thinning of the intervening liquid film to a (critical) thickness where the film ruptures, 2) rupture of the intervening liquid film and formation of a three-phase contact (tpc) nucleus (a hole of a critical wetting radius) and 3) expansion of tpc line from the critical radius to form a stable wetting perimeter (Chau et al., 2009).


T.T. Chau, W.J. Bruckard, P.T.L. Koh, A.V. Nguyen, A review of factors that affect contact angle and implications for flotation practice, Advances in Colloid and Interface Science 150 (2009) 106–115.